6’-sialyllactose (6’-SL) and 3’-sialyllactose (3’-SL) are the most abundant oligosaccharides in human milk, have anti-inflammatory properties and are involved in shaping the gut microbiome.
A recent study investigated the effects of sialyllactoses on the functioning of the intestinal epithelium, which were performed in human colorectal adenocarcinoma cells Caco-2, a model for the intestinal barrier. Polarised Caco-2 cells were treated with a mixture of 6’-SL and 3’-SL, RNA was extracted and prepared for transcriptomic analysis. The results revealed that 6’-SL and 3’-SL (from Carbosynth) modulated cell-cycle, in particular the pathways involving checkpoint control.
The sialyllactose mixture also affected epithelial homeostasis by regulating the balance between cell proliferation and differentiation. Treatment with high concentrations of sialyllactose lead to supressed cell proliferation and increased activity of a differentiation marker for enterocytes, alkaline phosphatase, and directed cells toward differentiation.
The study also showed that sialyllactoses affected the functioning of gut epithelia and induced re-epithelisation of mechanically damaged cells. This was performed in an in vitro wound healing assay in polarised immortalized gingival cells. Confluent cultures were damaged by scratches and their healing process was monitored by measuring the lag time and repair rate within the scratch area.
For more details, read the original paper published in the Frontiers in Immunology: Perdijk et al., 2019.